sure. I think I would start by reading some doco. Especially the create database statement.
-----Original Message----- D'mello Sent: Saturday, December 15, 2001 6:30 AM To: Multiple recipients of list ORACLE-L Is it possible to create a database without using dbassist ? Gavin ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Saturday, December 15, 2001 5:25 PM > This is not outdated -- the Oracle queries against the data dictionary > tables are tuned for RULE and so analyzing the SYS tables wreaks havoc > in the database. > > > --- Amar Kumar Padhi <[EMAIL PROTECTED]> wrote: > > My information on this may be a bit outdated. I had read it somewhere > > that > > statistics are not to be generated for SYS tables. Oracle will handle > > the > > dictionary information access, irrespective of the optimizer mode > > being > > used. The setting of the optimizer_mode should affect the application > > queries being generated for other schemas. So if you are using CBO, > > setting > > the Optimizer_mode to first_rows looks more applicable than doing an > > alter > > session every time. I am not able to comment on the poor performance > > when > > accessing the dict. > > > > rgds > > amar > > > > -----Original Message----- > > Sent: Friday, December 14, 2001 11:00 PM > > To: Multiple recipients of list ORACLE-L > > > > > > FYI, > > > > I just logged a call with Oracle re. Designer 6.0 vs. > > all_cons_columns. > > > > A developer noticed that whenever he queries that data dictionary > > table as > > part of generating database from server models, the process slows > > down to a > > crawl. > > > > If the target doesn't have any constraints, no problem. > > > > I am starting to wonder if it isn't because FIRST_ROWS was specified > > on this > > database, most of the developers are developing forms (6i) so I set > > the > > init.ora parameter accordingly. > > > > The Oracle documentation however implies that the CBO only switches > > to rule > > when there are no stats if optimizer_mode had been set to CHOOSE, if > > it's > > either ALL_ROWS or FIRST_ROWS it tries to use the CBO against the > > data > > dictionary anyway. How the CBO can run when there are no stats > > probably > > means it defaults to full table scans (?). > > > > OPTIMIZER_MODE = { all_rows | first_rows | rule | choose } > > > > The OPTIMIZER_MODE parameter specifies the approach and mode of the > > optimizer for your session. > > > > > > See Also: Oracle8i Concepts <../../server.817/a76965/toc.htm> and > > Oracle8i > > Performance Guide and Reference <../../server.817/a76992/toc.htm> > > for > > information on how to choose a goal for the cost-based approach based > > on the > > characteristics of your application > > > > > > > > * all_rows specifies the cost-based approach and optimizes for best > > throughput. > > * first_rows specifies the cost-based approach and optimizes for best > > response time. > > * rule specifies the rule-based approach. (The rule-based optimizer > > does not use function-based indexes.) > > * choose causes the optimizer to choose an optimization approach > > based > > on the presence of statistics in the data dictionary. > > > > Is this correct? If so, then I suppose I should set the init.ora > > parameter > > back to optimizer_mode=choose, and tell each developer to put an > > alter > > session statement on their clients to alter their sessions > > automatically to > > first_rows. The developer using designer will then be able to run it > > in a > > timely manner. > > > > Please tell me if my suspicion is correct. > > > > If correct, it begs the question: why are first_rows and all_rows > > available > > for the init.ora file??? > > > > Regards, > > Patrice Boivin > > Systems Analyst (Oracle Certified DBA) > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.com > > -- > > Author: Boivin, Patrice J > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > > San Diego, California -- Public Internet access / Mailing > > Lists > > -------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > > the message BODY, include a line containing: UNSUB ORACLE-L > > (or the name of mailing list you want to be removed from). You may > > also send the HELP command for other information (like subscribing). > > > > > __________________________________________________ > Do You Yahoo!? > Check out Yahoo! Shopping and Yahoo! Auctions for all of > your unique holiday gifts! Buy at http://shopping.yahoo.com > or bid at http://auctions.yahoo.com > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Rachel Carmichael > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Gavin D'mello INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Kimberly Smith INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).